It is common practice to provide in a commercial building air ducts through which air may flow from a furnace, boiler, air conditioner, and the like to one or more areas in the building. It also is common practice to install in one or more of such ducts a damper which normally is in an open or retracted position enabling air flow through the duct. However, when ambient temperature rises as a result of a fire or over-heated condition a fusible link assembly responds to a predetermined increase in ambient temperature and enables the associated damper to move from its air-passing position to its air-blocking position, thereby minimizing the supply of air to the affected area.
Most state and municipal codes require the fire dampers to be tested periodically to ensure their operability. Many fire dampers are of the kind wherein the damper is supported in its air-passing position by a collapsible strut composed of separable fusible links. Testing of such a damper assembly requires relocating of the fusible strut from its damper-supporting position to a position free of the damper, thereby enabling the latter to move to its air-blocking position. Following the test, the damper is returned manually to its retracted, air-passing position and the fusible strut is manually returned to its damper-engaging position.
The dampers are installed in strategic positions within the ducts and each duct within which a damper is installed has an access or inspection opening by means of which a technician may gain access to the damper for cycling it between its air passing and air-blocking positions. However, these openings usually are fairly small in area so as to avoid the creation of air leaks. As a consequence, access to the fusible strut and damper is quite limited, thereby making it difficult for the damper to be tested and reset properly. In addition, the access to the damper assembly often is obstructed by the presence of pipes, ducts, cables, and the like which are adjacent or within the air duct. Consequently, visual inspection and manual actuation of the damper assembly are hampered.
A principal objective of the apparatus disclosed herein is to provide a damper and collapsible support assembly which is easily operable for test purposes and manually resettable even though visual and manual access to the damper assembly is less than ideal. Another objective is to provide tactile evidence that the support assembly is returned to its proper position following testing.